Artificial turf sport fields are well-known in the prior art. They are generally used to replace natural grass surfaces and comprise rows of synthetic ribbons that extend vertically from a backing layer. The synthetic ribbons are designed to resemble grass and an infill layer of particulate material is often interspersed between the ribbons on the backing layer. In this arrangement, the synthetic ribbons are designed to extend a distance above the infill layer of particulate material. It is known in the prior art that the infill may comprise sand, rubber, a mixture of sand and rubber or other granulated particles such as TPE and epdm rubber. The infill of particulate material provides resiliency to the surface and helps keep the ribbons in an upright position.
Generally, the ribbons and backing of artificial turf known in the prior art is formed by tufting the ribbons through one or more layers of backing. The backing may comprise a single layer of material or multiple layers of material, and the individual layers may be either woven or nonwoven material.
The tufting is generally done using a conventional tufting machine, which is a giant sewing machine with hundreds of needles. Multiple ends of yarn are fed to a bank of heavy needles with a span of twelve to fifteen feet. The tufting process involves a previously constructed primary backing passing under the needles and anchoring each stitch. The ribbons are thereby stitched into the backing fabric, leaving loops which form the turf pile. The pile may be loop pile, or cut pile or a combination of cut and loop introduced simultaneously in the turf by pushing off certain loops from the hook before they are cut.
Once the ribbons are tufted in place through the primary backing, the backing is further coated on its back side with a urethane or latex coating, often referred to as a secondary backing, to help adhere the stitched ribbons to the backing member and to provide dimensional stability.
Artificial turf known in the prior art has a number of drawbacks. For example, the amount of force needed to pull a ribbon from the backing (tuft bind) for tufted artificial turf is sometimes lower than desired. Also, it is often difficult to program and manufacture tufted turf having different colors and designs as it requires manually changing the polyethylene, polypropylene or nylon pile being fed into the tufting machine and/or cutting design elements into the turf at installation. Accordingly, it would be beneficial to provide artificial turf which securely holds the ribbons in place and allows greater versatility in terms of the height and composition of the artificial turf ribbons as well as the color and design of the turf.